5.0 arcing between plug wires and outer plug

[maddog2112]

Hello all, Took my 06 5.0 Q6 out for a run first time yesterday . She ran fine but idled a little rough when leaving the lake. Checked her out when I got home and could hear a small clicking sound when running. When I looked at the spark plugs with a mirror, I could see arcing between 3 spark plug wire boots and the outer metal base of the spark plugs. I took the wires off and crimped them closed just a little to get a tighter fit. Same problem. Have never seen this before?? Wires are very good quality and have 2 seasons on them. So do the spark plugs. Any suggestions or experiences with this problem out there?

 

[alldodge]

It's not all that uncommon. If your getting the arching at the distributer cap, this is probably where the issue is and not the wires. It could still be the wires/boots but check the cap first

 

[bruceb58]

If you have spark plugs that are fouled or the gap is too large this can also happen. If the energy can't bridge the gap, the spark has to go somewhere and will find the path of least resistance. That is supposed to be your spark plug but if they are fouled or gapped too large for some reason, it will do what it is doing now.

 

[maddog2112]

Thanks for the responses. I have no arcing at the cap. I am going to replace my plugs with new R AC43ts. These are resistor plugs which someone recommended and I will apply dielectric to inner plug boots, all precautionary. Will keep you posted on my results.

 

[maddog2112]

Mystery solved. Once I removed the spark plugs, I was able to see the cracks in the 4 spark plug ceramics that had been sparking. Strange thing is, I just replaced my old with those plugs last season. It`s easy to have the extension and socket on the plugs a little crooked, or to over torque the plugs when installing. I`m guessing that`s what probably happened last season, or the plugs I had on cannot handle the heat. Thanks for the responses, and happy boating all.

 

[bruceb58]

If you can, use a torque wrench when installing your spark plugs.

 

[maddog2112]

Good advice Bruceb58. My Seloc mercruiser manual shows 15lbs torque, which I used this time.